-LRB- CNN -RRB- -- Protesters took to St. Louis streets for a second night Thursday after an off-duty officer killed a teen who fired at him three times , authorities said .

Chants of `` no justice , no peace '' rang into the night as crowds rallied after the Wednesday evening shooting . `` We pay you . You 're our employees ! '' a protester shouted .

Police arrested eight people : five on accusations of unlawful assembly , two for alleged property damage and one on a marijuana possession charge , St. Louis police spokeswoman Schron Jackson said .

One officer suffered minor injuries and two police cruisers were damaged , Jackson said .

`` I think the officers showed a tremendous amount of restraint , '' St. Louis Police Chief Sam Dotson told CNN affiliate KMOV .

Protesters also burned at least one American flag , CNN affiliate KSDK reported . That did n't go over well with some .

`` These protesters in Saint louis burning American flags makes me sick , '' Twitter user AllenVA75 posted . `` brave men and women in uniform died for that flag , and they burn it ? ''

But others defended the burning .

Twitter user PontifexMonty said `` people really getting mad that they 're burning the flag in St. Louis . not about the black teens that are dead , the burning flag . ''

The teenager , Vonderrit Deondre Myers , was struck by seven or eight bullets , said Dr. Michael Graham , a St. Louis medical examiner

`` All but one gunshot wound were to the lower extremities , '' Graham said . `` The one fatal wound was to the head . ''

Police said the teen fired a pistol three times at an off-duty St. Louis officer who was wearing his uniform while moonlighting for a security company . The officer fired back 17 times , authorities said .

Angry protesters pointed out similarities to the August killing of Michael Brown in nearby Ferguson .

Myers and Brown were both 18 , African-American and killed by white police officers . One big difference : Police said Brown was unarmed .

iReport video : Shots fired at St. Louis protest

`` It 's a clear case of this young man being gunned down by an insensitive white officer who was off-duty , '' Akbar Muhammad , who also is a member of a coalition calling for the officer who shot Brown to be prosecuted , told CNN affiliate KTVI .

Neil Bruntrager , a lawyer for the St. Louis Police Officers ' Association , dismissed accusations that 17 shots were excessive .

`` When he uses deadly force , he uses deadly force until the threat is gone , '' he said on `` Erin Burnett OutFront . ''

Without video of the incident or unbiased witnesses , the police and the public must rely on physical evidence , he said . A 9 mm pistol allegedly fired by Myers was found at the scene , police said . It was jammed , which shows that it had been fired , Bruntrager said .

But Van Jones , a civil rights activist and CNN contributor , said there 's a lot of police mistrust after the Brown killing .

`` You 're seeing a wholesale breakdown of trust , '' he said .

The officer , a six-year veteran who has not been named , was placed on administrative leave . He served two tours of duty with the military in Iraq and was awarded a Bronze Star and a Purple Heart , Bruntrager said .

While on patrol , the officer saw three men run away as he approached , Dotson said . He chased them after one held up his pants in a way that made the officer believe he may be carrying a gun , Dotson said .

The officer tussled with one teen , who ran off , then turned around and fired at least three shots toward him , Dotson said .

The officer returned fire , killing the teen .

Additional marches are planned over the weekend around the St. Louis region , organizers said .

CNN 's Shawn Nottingham contributed to this report .

@highlight

NEW : Flag burning at protest provokes strong reactions

@highlight

Police make eight arrests in St. Louis protests , department spokesman says

@highlight

The officer , who has not been identified , is on leave , police association lawyer says

@highlight

A 9 mm pistol allegedly fired by the teen was found at the scene